Modern wind turbine blades generally combine low weight and low rotational inertia with high rigidity and high resistance to fatigue and wear so as to withstand the various forces and the extreme conditions encountered over a typical life cycle. Generally described, the turbine blades may be formed from two shell halves. A critical step in the manufacture of the turbine blade is the closing of the two shell halves of the blade at a leading edge, a trailing edge, and at a spar cap union with a shear web via an adhesive to create a bond joint. Verifying the width and the overall integrity of this adhesive bond is required to ensure that the turbine blade will meet performance and lifetime requirements. Failure of the turbine blade along the bond joint could lead to significant damage.
Current methods for the inspection of this adhesive bond joint include visual inspection and various types of non-destructive imaging inspection techniques such as ultrasonic testing. Such ultrasonic testing, however, may be time consuming and relatively costly. Moreover, some of the blade materials may be difficult to penetrate via ultrasound. Specifically, certain areas of the blade may be obscured from ultrasonic testing because of the use of foam, balsa, or other types of core materials that may not pass typical ultrasonic frequencies therethrough. Certain types of microwave inspection techniques also are known. Such microwave inspection, however, may be limited by exposure to radiation.
There is thus a desire for improved systems and methods of inspecting an adhesive bond joining the halves of a wind turbine blade. Preferably such systems and methods may accurately and reliably inspect the entire adhesive bond joint without requiring expensive and time consuming ultrasonic testing and the like.